Steam-valve



UNITED STATES PATENT OFFICE.

JOHN E. VVOO'ITEN, OF PHILADELPHIA, PENNSYLVANIA.

STEAM-VALVE.

Specification of Letters Patent No.

To all whom it may concern:

Be it known that I, JOHN EVVOOTTEN, of Philadelphia, in the county of Philadelphia and St-ate of Pennsylvania, have invented a new and Improved Mode of Balancing the Pressure of Slide-Valves of Steam-Engines upon Their Seats; and I do hereby declare that the following is a full, clear, and exact description of the construction and operation of the saine, reference being had to the annexed drawings, making a part of this specification, in which- Figure l is a perspective view of steam chest, and pressure chamber, surmounting same. Fig. 2 is a longitudinal sectional elevation of the steam chest and parts comprising my improvements, Fig. 3 is a transverse sectional elevation of same. Fig. a is a perspective view of the parts contained within the steam chest. Fig. 5 is a perspective view of same, but with a portion of stirrup G, removed for the purpose of showing the arrangement of anti-friction roller L within the box I. Fig. 6 represents in perspective an anti-friction roller, the use of which will be hereinafter described.

Similar letters refer to similar parts.

The nature and construction of my irnprovement is as follows:

A steam tight chamber is formed by uniting the two sections C and D, with a ring or diaphragm E of india rubber cloth or other fiexible or elastic material. The upper sec tion D may be considered as a piston acted upon by the steam pressure, free communication being open between it and the interior of steam chest F by means of a passage through the lower section C of chamber. Through the center of chamber and extending into the steam chest is a stem H, which is supported in its proper position by nut M. Attached to the lower end of stem H, and within the steam chest is a stirrup G which is held steadily in place by the projecting ends thereof coming in contact with the walls of steam chest, but atV the same time should be free to move upward or downward when required to do so. On top of .stem H, is placed an oil cup A, and an opening through the stem H, admits of the introduction of oil to the interior of steam chest. On top of slide valve B, is secured a box I, a portion of the ends of which is removed for the purpose of per- Vmitting the bottom of stirrup G to pass freely through the opening. Within the box 22,599, dated January 11, 1859.

yI, is placed an anti-friction roller L, the

use of which will be hereinafter described.

K, is a plate covering the top of box I, and is securely fastened thereto.

Having thus described the construction of my improved mode of balancing slide valves, I will proceed to describe the operation of same, which is as follows Steain having been admitted within the pressure chamber, the upward pressure against piston D, is exerted upon stirrup G, by means of nut M, and stem I-I, and transmitted to valve B, by means of anti-friction roller L, interposed between stirrup G and plate K. The slide valve B is therefore subject to a force tending tc lighten it upon its seat, equal to the upward pressure exerted upon piston D. As valve B moves apon its seat, the anti-friction roller L moves also in same direction upon stirrup G. The space for action of anti-friction roller L, is limited by the ends of box I, the distance between the two ends of box I, being equal to one half the throw of valve B, in addition to the diameter of roller, with a small additional allowance of room for clearance at the end of the throw. By confining the roller within these limits it is kept while in motion as near as practicable to the centers of valve B and stirrup G respectively.

I would remark, that I do not wish to confine myself strictly to the mode herein described, as modifications of substantially the same arrangement may be required to meet peculiar circumstances. For instance an elastic disk of metal may be placed upon the cover of steam chest, and exposed to the upward pressure of steam. If the stem I-Ibe connected with such a disk and the parts properly adjusted, the effect would be the same to a certain extent as with my arrangement hereinbefore described. Another modification might be instanced, where the cover of the steam` chest would be sufficiently elastic and yielding that advantage could be taken of those properties to produce the required result. I prefer however the arrangement as shown upon the drawings, as from the flexibility and range of motion possessed by the diaphragm E it has the advantage of preserving a uniformly proportional upward strain upon the slide valve as the parts may wear. Theremay also be modifications of the arrangement of the anti-friction roller L, as for instance, the roller may be mounted upon trunnions, the

bearings for which may be Xed either upon the stirrup G or valve B, but I refer the arrangement shown, by reason o its being accompanied With the minimum of friction, as Well as themleast deviation from the center of stirrup Gr or valve B, respectively by the anti-friction roller L as it traverses upon its seat.

Having thus fully described the construction and operation of my improved mode of balancing` the pressure upon slide Valves,

what I claim and desire to secure by Letters Patent is- The application of the anti-friction roller L in combination With a diaphragmatic piston D, or an equivalent therefor, substantially as and for the purpose herein set forth.

J. E. W'OOTTEN. Witnesses:

F. MCCONMYTON, lV. A. BOYD. 

